D-amino acid-substituted atrial natriuretic peptide analogs reveal novel receptor recognition requirements

J Biol Chem. 1988 Nov 15;263(32):16818-22.

Abstract

The introduction of D-amino acid residues into peptide hormones has been traditionally utilized in structure-activity studies to probe the conformational requirements of ligand-receptor interactions. A study was undertaken to examine the effect of D-amino acid substitutions into the atrial natriuretic peptide molecule on interactions with distinct subpopulations of specific membrane-associated receptors of bovine aortic smooth muscle cells. Competitive binding analysis revealed that each of 15 synthetic D-amino acid-substituted analogs showed comparable affinities for C-ANP receptors, a class of specific receptors which have been proposed to mediate the sequestration and metabolic clearance of ANP. The relative affinities of all 15 analogs did not differ more than 10-fold. In contrast, the interaction of the ANP analogs with a second receptor pool (B-ANP receptors), which is coupled to the stimulation of particulate guanylate cyclase, varied over a 1000-fold range of potency consistent with expectations for a receptor that displays rigorous conformational specificity. The indiscriminant selectivity of C-ANP receptors for D-amino acid-substituted ANP analogs is unprecedented for hormone receptors involved in biological signal transduction. These results, when coupled with the inability to correlate any direct in vitro biological effect associated with C-ANP receptor occupancy supports the hypothesis that the C-ANP receptor protein is a novel transport protein involved in the metabolic clearance of ANP.

Publication types

  • Comparative Study

MeSH terms

  • Affinity Labels / metabolism
  • Amino Acids / analysis*
  • Animals
  • Atrial Natriuretic Factor / analysis*
  • Binding Sites
  • Binding, Competitive
  • Cattle
  • Cyclic GMP / pharmacology
  • Muscle, Smooth, Vascular / drug effects
  • Muscle, Smooth, Vascular / metabolism
  • Structure-Activity Relationship

Substances

  • Affinity Labels
  • Amino Acids
  • Atrial Natriuretic Factor
  • Cyclic GMP